Mangekyō Sharingan
The is a heightened form of Sharingan. The Mangekyo Sharingan is distinguished from a normal Sharingan through its appearance, which changes the form of the tomoe seal. However, unlike the Sharingan, it has a different appearance between the users, as a kaleidoscope never looks the same when looked through. Kakashi's version is significantly different than Itachi's, as Madara's looks completely different, and his brother's looks different also. Those who have the potential to obtain it must make a great sacrifice in order to obtain it – according to Itachi, they must kill their closest friend. Itachi, Madara, and his brother apparently do in fact do this to obtain the original version, but Kakashi has noted that everyone he cared about had died long before the start of the series, so how he developed his own variant is unknown. The major drawback of the Mangekyo Sharingan is that when it is first activated, it slowly begins to destroy the eyes, until the user becomes completely blind. The only way to regain one's eyesight after losing it would be to steal the eyes of a sibling, combining the two Sharingan to create a new, more powerful, and immortal Mangekyo Sharingan, which prevents blindness and apparently grants immortality. In the long history of the Uchiha clan, only a few have been able to obtain the Mangekyo Sharingan, Madara Uchiha being the first, and his brother being the second. At present, there are three live people who can use the Mangekyo Sharingan: Kakashi, Madara, and Sasuke, although getting his from his brother, Itachi, from unknown methods. Mangekyo Sharingan can release 3 deadly jutsus, they are Tsukuyomi, Amaterasu, and Susano'o. Although these jutsu are extremely devastating, they require an enormous amount of chakra, and also cause immense strain and eventually blindness on the user. The same may not be said about Susano'o, however, since Itachi was out of chakra when he decided to use it. Susano'o may not even require Mangekyo Sharingan to be activated, but the Mangekyo Sharingan must at least be obtained. Mangekyo Sharingan Variations Itachi Uchiha Itachi Uchiha gained the Mangekyo Sharingan by killing his best friend, Shisui Uchiha. With the Mangekyo Sharingan, Itachi is able to use the three most powerful jutsu of the Uchiha clan. The first is Tsukuyomi, a powerful genjutsu. This jutsu comes out of and puts strain on the left eye. Upon making eye contact with an opponent, Itachi can use Tsukuyomi to transport them to an illusionary world where days amount to a mere moment in reality. Because Itachi is in total control of this world, he can torture an opponent in any way imaginable, leaving them crippled and in a state of mental collapse, though he hasen't gone further than 3 days. The second jutsu is Amaterasu. This jutsu puts strain on the right eye, and causes his eye to bleed. Described by Zetsu as the ultimate ninjutsu, it is shown to be capable of burning through almost anything by creating a jet-black flame said to be as hot as the sun and capable of burning for seven days and seven nights. Where Amaterasu is released from is unsure (wether the mouth, or the eye or out of nothing), but it is most probably the first choice or the last choice since you can't see Sasuke opening his mouth when attacking unintentionaly Madara. But you couldn't see it coming out of his eyes too, but only manifest directly next to Madara. The final and most powerful of these jutsu, is the devastating Susano'o. The taijutsu summons a massive inhuman spiritual warrior, which then fights on behalf of Itachi. It is possible that Susano'o puts a strain on the heart, since Itachi began to cough up blood from using the jutsu. The warrior wields a shield in its left hand, and in its right, the legendary Totsuka no Tsurugi (十拳剣, lit. "The Sword Ten Hands Long"?), also known as the Sakenagi Longsword (酒刈太刀, Sakenagi Tachi?, lit. "Sake Cutter Longsword"). The Totsuka no Tsurugi, commonly sheathed in a sake jar held by a third hand growing from Susanoo's right forearm, is an ethereal weapon with an enchanted blade capable of sealing anything it pierces in an eternal dream-like illusion, and is described as the perfect counter to Orochimaru's Kusanagi Sword. All of these jutsu, however, use massive amounts of chakra and also cause ever increasing damage to the user's eyesight, as the eyeball itself is engorged in blood and stressed enormously while being used; Itachi himself becomes exhausted if using them both consecutively and has to deactivate his Sharingan. Soon his ulterior motive is revealed, which would be to steal Sasuke's eyes to awaken his own Eternal Mangekyo Sharingan. During the fight with Itachi and Sasuke, Zetsu has revealed that the "Left Mangekyo" possesses the Tsukuyomi and the "Right Mangekyo" holds Amaterasu. Interestingly, each respective eye seems to bleed when the respective technique is used. It is unknown where Susano'o comes from, possibly the heart due to the fact that Itachi's heart was focused on at one point. It is unkown if Itachi even needs the Mangekyo Sharingan to make it work, it is merely known that he needs to have at least awakened it to use it and his eyes were not in the Mangekyou Sharingan-Mode while using this technique. Kakashi Hatake Kakashi Hatake developed his own version of the Mangekyo Sharingan during the timeskip. Kakashi uses his to create a localized interdimensional space-time warp, allowing him to target any object and send it to another dimension. The attack requires considerable effort to aim precisely and appears to leave Kakashi's chakra significantly drained; he collapses after using the technique three times in a single day (compared to his other original move, Lightning Blade, which he can use four times a day). The appearance of the pupil and tomoe in Kakashi's Mangekyo Sharingan differ from that of Itachi's; Kakashi's looks more like a pinwheel. Before this was shown, it was thought that one had to kill their best friend to acquire the Mangekyo Sharingan. Given that Kakashi is unlikely to do this, due in part to his own admittance that everyone close to him is already dead, the means behind its development and the actual meaning of the "requirement" are currently unknown. The difference in both look and abilities of Kakashi's, Itachi's, and Madara's Mangekyo Sharingan suggests that each Mangekyo Sharingan's attributes differ from one user to another. Madara Uchiha Madara Uchiha was actually the first person to wield this dangerous weapon. When he was young, he and his younger brother were the first people to gain the Mangekyo Sharingan. He eventually grew blind from it, and possessed by the Mangekyo Sharingan he killed his younger brother and stole his eyes. This unlocked the "Eternal" Mangekyo Sharingan. Madara used its power to control the power of the Nine-Tailed Demon Fox and sent it to attack Konoha, but failed because of the Fourth Hokage's sacrifice. The Eternal Mangekyo Sharingan in appearance looks identical to Madara's first Mangekyo combined with his younger brother's Mangekyo. The Eternal Mangekyo Sharingan also seemingly grants the user immortality and, according to Itachi, a fourth and final eye technique, which is the reason why Itachi Uchiha spared his younger brother Sasuke - hoping to take Sasuke's eyes to achieve the Eternal Mangekyo Sharingan for himself. As stated by his goal, to use the Tailed Beasts to return his Sharingan to its former power and that Itachi said he was only a shell of his former self it would seem that Madara's Sharingan has been damaged some time after taking control of the Nine-Tailed Demon Fox. Sasuke Uchiha After Sasuke's battle with Itachi, he wakes up in a cave, with Madara nearby. Madara removes his mask to reveal his Sharingan, which upon sight triggers the activation of Sasuke's Mangekyo Sharingan and the Amaterasu, setting Madara ablaze. However Sasuke seems to have no control of this and quickly clamps his eyes together. Like with Itachi, Sasuke's eyes also begins to bleed when he uses Amaterasu, indicating that he not only has no control of the technique, but that it also seems to put some strain on him. Madara then explains that Itachi properly transferred all of his eye techniques to Sasuke, to protect his little brother, as a fail safe. It should be noted that unlike the other Mangekyo Sharingan variants, Sasuke's looks identical to Itachi's most likely because it is actually Itachi's dōjutsu transferred to him.